<template>
  <view>
    <view class="scroll-view-container">
          <!-- 左侧的滚动视图区域 -->
          <scroll-view  class="left-scroll-view" scroll-y="true" :style="{height: wh + 'px'}">
             <block v-for="(item, i) in cateList" :key="i">
               <view :class="['left-scroll-view-item', i === active ? 'active' : '' ]" @click="activeChanged(i)">{{item.cat_name}}</view>
             </block>
              <view class="left-scroll-view-item">xxxx</view>
            
          </scroll-view>
          <!-- 右侧的滚动视图区域 -->
          <scroll-view  scroll-y="true" :style="{height: wh + 'px'}" :scroll-top="scrollTop">
            <view class="cate-lv2" v-for="(item2, i2) in cateLevel2" :key="i2">
              <!--二级分类的标题-->
              <view class="cate-lv2-title">/ {{item2.cat_name}} /</view>
              <!--当前二级分类下的三级分类列表-->
              <view class="cate-lv3-list">
                <!--三级分类的item项-->
                <view class="cate-lv3-item" v-for="(item3, i3) in item2.children" :key="i3" @click="gotoGoodsList(item3)">
                  <!--三级分类的图片-->
               <image :src="item3.cat_icon"></image>

                 <!--三级分类的文本-->
                 <text>{{item3.cat_name}}</text>
                </view>
  
              </view>
              
            </view>
          </scroll-view>
        </view>
  </view>
</template>

<script>
  export default {
    data() {
      return {
        //当前设备可用高度
        wh: 0,
        cateList: [],
        active: 0,
        //二级分类的列表
        cateLevel2: [],
        scrollTop: 0
      };
    },
    onLoad() {
      const sysInfo = uni.getSystemInfoSync()
      console.log(sysInfo)
      this.wh = sysInfo.windowHeight
        this.getCateList()
      
    },
    //获取分类列表的数据
    methods: {
     async getCateList(){
         const { data: res } = await uni.$http.get('/api/public/v1/categories')
          if (res.meta.status !== 200) return uni.$showMsg()
             this.cateList = res.message
             
             //二级分类赋值
            this.cateLevel2 = res.message[0].children
      },
      activeChanged(i) {
        this.active = i
        
        //重新为二级标题赋值
        this.cateLevel2 = this.cateList[i].children
        this.scrollTop = this.scrollTop === 0 ? 1 : 0
      },
      //跳转到商品页面
      gotoGoodsList(item3) {
        uni.navigateTo({
          url: '/subpkg/goods_list/goods_list?cid=' + item3.cat_id
        })
      }
    }
  }
</script>

<style lang="scss">
.scroll-view-container{
  display: flex;
  .left-scroll-view{
    width: 120px;
    
    .left-scroll-view-item {
          line-height: 60px;
          background-color: #f7f7f7;
          text-align: center;
          font-size: 12px;
          
          // 激活项的样式
                &.active {
                  background-color: #FFFFFF;
                   position: relative;
                  }
                   &::before {
                            content: ' ';
                            display: block;
                            width: 3px;
                            height: 30px;
                            background-color: #c00000;
                            position: absolute;
                            left: 0;
                            top: 1%;
                            transform: translateY(-10%);
                          }
                  
  }
}
}
.cate-lv2-title{
  font-size: 12px;
  font-weight:bold;
  text-align: center;
  padding: 15px;
}
.cate-lv3-list{
  display: flex;
  flex-wrap:wrap;

.cate-lv3-item{
  width: 33.33%;
  display: flex;
  display: flex;
      flex-direction: column;
      align-items: center;
      margin-bottom: 10px;
  
  image{
    width: 60px;
    height: 60px;
  }
  text{
    font-size: 12px;
  }
}
}
</style>
